Materials application apparatus

ABSTRACT

A modular imaging electrode assembly for supplying liquids in automated imaging machines. The unit has a tank holding a roller coupled to an electrical source. The roller is driven past a liquid applying and leveling apparatus and then contacts an imaging member of the machine in which it is located. The tank which is elevated into and out of contact with the member of the machine has two or more sections. The first houses the apparatus to apply liquid to the roller and the second has cleaning brushes in it to remove any materials remaining on the roller. Optionally, a third section applies a different liquid to the roller. The sections are separated by squeegees for preventing material in the one section from affecting that in another.

United States Patent 1 Egnaczak Mar. 27, 1973 [54] MATERIALS APPLICATION APPARATUS [75] Inventor: Raymond Keith Egnaczak, Williamson, N.Y.

[73]- Assignee: Xerox Corporation,, Rochester,

22 Filed: Apr. 21, 1972 [21] Appl. No.: 246,446

[52] US. Cl. ..355/3, 355/4, 355/10, 1 18/637 [51] Int. Cl. ..G03g 15/00 [58] Field of Search ..355/3, 4, 10; 96/12, 1.3;

[56] References Cited UNITED STATES PATENTS 3,642,606 2 1972 Zucker ..96/l.3X

Primary ExaminerRobert P. Greiner Attorney-James J. Ralabate et a1.

[57] ABSTRACT A modular imaging electrode assembly for supplying liquids in automated imaging machines. The unit has a tank holding a roller coupled to an electrical source. The roller is driven past a liquid applying and leveling apparatus and then contacts an imaging member of the machine in which it is located. The tank which is elevated into and out of contact with the member of the machine has two or more sections. The first houses the apparatus to apply liquid to the roller and the second has cleaning brushes in it to remove any materials remaining on the roller. Optionally, a third section applies a different liquid to the roller. The sections are separated by squeegees for preventing material in the one section from affecting that in another.

7 Claims, 8 Drawing Figures PATENTEUHARZHHH SHEET 2 OF 5 WNW IIII NMN QVN mmN SHEET 3 BF 5 PATENTEUHARZTIQIS PATENTFnHmHm 722,993

1 MATERIALS APPLICATION APPARATUS This invention relates to imaging systems and more particularly to liquid application tank assemblies.

Recently, a new invention was disclosed for forming black and white or full color images through the use of photoelectrophoresis. The inventions described in U.S. Pat. Nos. 3,384,488; 3,384,566 and 3,383,993 disclose a system where photoelectrophoretic particles migrate in image configuration providing a visual image at one or both of two electrodes between which'the particles are placed in suspension. The particles are photosensitive and apparently undergo a net change in charge polarity or a polarity alteration by interaction with one of the electrodes upon exposure to activating electromagnetic radiation. No other photosensitive ele ments or materials are required; hence, this provides a very simple and inexpensive imaging technique. Mixtures of two or more differently colored particles can secure various colors of images. Particles in these mixes may have overlapping or separate spectral response curves and are usable in subtractive color synthesis. The particles will migrate from one of the electrodes under the influence of an electric field when struck with energy of a wavelength within the spectral response of the colored particles.

Apparatus has been invented to better utilizes the above process. For example, a continuous imaging machine was disclosed in U.S. Pat. No. 3,427,242 depicts apparatus for utilizing the photoelectrophoretic process of the above patents. Copending application Ser. No. 876,976 filed on Nov. 12, 1969 now U.S. Pat. No. 3,642,365, in the name of Raymond K. Egnnczak and Gino F. Squassoni and entitled Automated Imaging Machine is a more sophisticated embodiment of a machine utilizing the new process to produce true color reproductions of original documents or the like. In order to form a particularly good image with the apparatus described therein one or more imaging elec trodes must interface with the injecting electrode or imaging member under the proper conditions for photoelectrophoretic imaging to occur. This must be accomplished automatically and precisely with proper components engaged for processing to be achieved.

Therefore, it is an object of this invention to improve imaging electrode mechanisms. Another object is to improve tanks used for liquid application and removal.

' Another object of this invention is to automatically provide imaging suspension at the imaging member under the proper photoelectrophoretic conditions.

Still another object of this invention is to apply liquids to and clean surfaces.

Yet another object of this invention is to supply imaging suspension ready for imaging between electrodes of a photoelectro-phoretic imaging system.

These and other objects of this invention are accomplished by providing a tank with means to supply liquids to a surface for bringing the liquid to a work station. Meansare included to prevent used liquids from remaining on the surface. Means are provided to move the tank holding the surface and application and cleaning components into and out of the work station.

These and other objects and advantages will become apparent to those skilled in the art after reading the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 schematically illustrates a preferred embodiment of a machine for forming photoelectrophoretic images;

FIG. 2 is a plan view partially broken away to show hidden parts of the imaging electrode assembly and tank;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a side view, with hidden parts dotted, of the imaging electrode module;

FIG. '5 is a side view, with hidden parts dotted, of the imaging electrode module as viewed from the side opposite FIG. 4;

FIG. 6 is a partially sectioned view taken along line 6-6 of FIG. 4;

FIG. 7 is a sectional view of an alternative embodiment of the apparatus; and

FIG. 8 is a side view of the controls for the parts of FIG. 7.

The invention herein is illustrated and described in a preferred environment embodiment operating in conjunction with other apparatus to automatically and continuously produce images of predetermined optical objects. Nevertheless, the invention need not be confined to such an embodiment and should be construed broadly within the limitations of the claims. It may be that other processes or apparatus will be invented having similar needs to those fulfilled by the apparatus described and claimed herein and it is the invention herein to describe an invention for use in other apparatus than in the embodiment shown. Various specific apparatus is described for accomplishing a par ticular function, but any equivalent structure can be substituted and still be within the scope of the invention.

OPERATION OF BASIC PHOTOELECTROPI-IORETIC SYSTEM A detailed description of the operation and theories relating to the actual imaging system automated by this invention and discussing the interaction of the photoelectrophoretic particles in the suspension used for image formation is found in the above cited patents. The imaging system therein described and which can be employed in the apparatus described herein operates by producing electromagnetic radiation in image configuration to which the individual photoelectrophoretic particles within the suspension are sensitive. The activating radiation and an electric field across the imaging suspension combine between two electrodes in the imaging area. An electrode referred to as the transparent injecting electrode is maintained electrically positive relative to imaging electrodes interfacing with it at the imaging area across the photosensitive suspension. Therefore, particles within the suspension that are negatively charged will be attracted to the relatively positive, transparent injecting electrode. I

The injecting electrode is so named because it is thought to inject electrical charges into activated photosensitive particles during imaging. The term photosensitive for the purposes of this invention refers to the property of a particle which, once attracted to the injecting electrode, will alter its polarity and migrate away from the electrode under the influence of an applied electric field when exposed to activating electromagnetic radiation. The term suspension may be defined as a system having solid particles dispersed in a solid, liquid or gas. Nevertheless, the suspension used in the embodiment of this invention described herein is of thegeneral type having a solid suspended in a liquid carrier. The term imaging electrode is used to describe that electrode which interfaces with the injecting electrode through the suspension and which once contacted by activated photosensitive particles will not inject sufficient charge into them to cause them to migrate from the imaging electrode surface. The imaging zone or imaging area is that zone between two electrodes where photoelectrophoretic imaging occurs.

The particles within the suspension are generally insulating when not struck by activating radiation within their spectral response curve. The negative particles come into contact with or are closely adjacent to the injecting electrode and remain in that position under the influence of the applied electric field until they are exposed to activating electromagnetic radiation. The particles near the surface of the injecting electrode make up the potential imaging particles for the final image to be reproduced thereon. When activating radiation strikes the particles, it makes them conductive creating" an electrical junction of charge carriers which may be considered mobile in nature. The negative charge carriers of the electrical junction orient themselves toward the positive injecting electrode while the positive charge carriers move toward the imaging electrode. The negative charge carriers nearthe particle-electrode interface at the injecting electrode can move across the short distance between the particle and the surface of the electrode leaving'the particle with a net positive charge. These polarity altered, net positively charged particles are now repelledaway from the positive surface of the injecting electrode and are attracted to the negative surface of the imaging electrode. Accordingly, the particles struck by activating radiation of a wavelength with which they are sensitive, i.e., a wavelength which will cause the formation of an electrical junction within the particles, move away from the injecting electrode to the imaging electrode leaving behind, only particles which are not exposed to sufficient electromagnetic radiation in their responsive range to undergo this change.

Consequently, if all the particles in the system are sensitive to one wavelength of light or another and the system is exposed to an image with that wavelength of light, a positive image will be formed on the surface of the injecting electrode by the subtraction of bound particles from its surface leaving behind particles in the unexposed areas only. The polarities on the system can be reversed and imaging will occur. The system may be sure source. In polychromatic systems the particles may be selected so that particles of different colors respond to different wavelengths For photoelectrophoretic imaging to occur, these steps (not necessarily listed in the sequence that they occur) take place: l migration of the particles toward the injecting electrode due to the influence of the field, (2) the generation of charge carriers within the particles when struck with activating radiation, 3) particle deposition on or near the injecting electrode surface (4) phenomena associated with the forming of an electrical junction between the particles and the injecting electrode, (5) particle charge exchange with the injecting electrode, (6) electrophoretic migration toward the imaging electrode, and (7) particle deposition on the imaging electrode. This leaves a positive image on the injecting electrode.

After the image is formed on the injecting electrode I the electrode may be brought into interface with a transfer member which has a charge polarity opposite to that of the imaging electrode. The injecting electransfer member. If a support material is interposed operated with dispersions of particles which initially I may be of any color and produce any colorand the particle spectral response is relatively immaterial as long as there is a response in some region of the spectrum which can be matched by a convenient radiation expobetween the transfer member and the particle image, the particles will be attracted to the support material. Therefore, a photographically positive image can be formed on any support material.

THE MACHINE COMPONENTS Referring now to FIG. 1, a preferred embodiment for an automated machine to produce images according to the aforementioned process is shown. An injecting electrode 1 forms a portion of a transparent cylinder member held in a housing 2 and is journaled for rotation in the direction indicated by the arrow about a shaft 3. The injecting electrode 1 is made up of a layer of optically transparent glass 4 overcoated with a thin optically transparent layerS of tin oxide or other electrically conducting material. A particular material suitable for this electrode is available under the name of NESA glass manufactured by Pittsburgh Plate Glass Company, Pittsburgh, Pa. The injecting electrode 1 is formed as a portion of a cylinder housed within the metal housing frame 2.

The machine shown schematically. in FIG. 1 is positioned where the injecting electrode cylinder portion is about to be rotated in a predetermined path to a cleaning station labeled A whereat a plurality of cleaning members such as belts 6, 7 and 8 contact the conductive surface 5 of the injecting electrode. On the opposite side of the injecting electrode held stationary within the machine frame are lamps 9, l0 and 11 juxtaposed to the belts 6, 7 and 8 respectively. When activated, the lamps send flood light illumination through the transparent injecting electrode at the contact areas between the electrode and the cleaning belts. Each of the belts' are activated by one of the cylinders 12, 13 and 14 to contact the injecting electrode 1. These cylinders operate to press the belts against the conductive surface of the injecting electrode in order to clean It.

The next station in the path of movement of the injecting electrode is the inking and imaging station B.

Here, electrode 16 contacts the conductive surface 5 of the injecting electrode 1.

The optical system at station C projects an image to the imaging zone between the electrodes 1 and 16 at station B. The optical system has a lamp carriage l7 journaled at an axis l8 toioscillate in a path indicated by the arrows. A document is positioned at the platen 19. The lamps are shown at the start of scan position and as the injecting electrode 1 passes through the imaging area at station B the lamps move across the r platen 19 projecting an image at station B through suitable mirrors 21-23, a lens 24 and the transparent electrode 1. The scan is synchronized with the movement of the injecting electrode to project a flowing image in registration with the first projection and moving at the same rate as is the surface Sat the imaging zone.

The imaging electrode roller 16 moves in rolling interface relation with the conductive surface 5 of the injecting electrode 1 and functions both to supply suspension tothe injecting elect rode andto image that suspension between the injecting electrode surface 5 and the surface of the electrode 16.

The injecting electrode 1 then passes into the transfer station D. At station D is a transfer roller 40. A sheet of support material held in the supply tray 41 is lifted therefrom and is carried through a vacuum transport 42 to the transfer roller 40. It is gripped by a gripper mechanism 43 on the transfer roller 40 and rotated to the injecting electrode 1 passing at station D. Before the sheet 44 contacts the surface 5 of the inject ing electrode 1 it is moistened with a liquid that will aid in transferring the particles of the suspension on the surface 5. The wetting is accomplished by a wetting bar 45 rotated in a pool of suitable wetting material held within a tank 46. The transfer member 40 rotates the support material 44 in rolling contact with the surface 5 of the injecting electrode 1 under the influence of a suitable electric field causing the particles forming the image on the injecting electrode to be transferred to the support material. The support material is removed from the transfer member by picker fingers 47 and a release mechanism on the grippers. Next it is carried on a vacuum transport 48 to a suitable receptacle.

IMAGING ELECTRODE ASSEMBLY The image forming process occurs in the imaging zone at station B at the intersection between theinje'cting electrode 1 and the imaging electrode 16. It ishe re that the photoelectrophoretic particles are brought between the injecting and imaging electrodes for processing under an applied field and image radiation coming from the optical-system at the stationC.

Within the imaging electrode tank is the imaging electrode l6. mounted on its shaft 216 fastened at each end of the first imaging tank through-end caps 217 and 218 fitted into the tank side walls 219 and 220 respectively. The imaging tank 26 in this embodiment is broken into three sections. The cleaning sectionhouses a portion of the imaging electrode 16 and mechanisms to clean its surface and is bounded by the bottom plate 223, the end plate 221 and the tank splitting wall 222. I

the bottom plate 223. The mount section of the imaging electrode tank is open and adapted for maintaining some of the motors and solenoids necessary for the operation of the unit.

Located in the applicator portion of the imaging electrode tank are the mechanisms necessary to form a layer of suspension on the imaging electrode 16 for imaging at the imaging zone. There are two suspension supplying brushes 225 and 226 to carry suspension from the bottom of the applicator portion of the tank 26 in which they are located to the surface of the imaging electrode 16. The brushes are mounted on a support 227 having two arms 228 and 229 into which the shafts 230 and 231 of the two applicator brushes are mounted. The shafts mount into the arms through four bearings 232-235 and four collars such as collar 236 holdingthe shaft 230 onto the arm 238 through the bearing 233. I

In order to ensure that a smooth layer of suspension reaches the intersection of the imaging electrode with the injecting electrode, a smoothing rod such as a wound wire rod 237 is made to be moved into contact with the imaging electrode 16. The rod can be grooved, smooth, knurled or have any surface for passing a uniform thin layer of suspension. The smoothing rod is mounted by two support arms 238 and 239 into the side walls 219 and 220 of the imaging electrode tank. It mounts thereat through bearings 241 and 242 and extends through the tank wall 219 into a crank arm 243 fixedly mounted on it. The shaft 240 is preferably a torque tube so that when it rotates the smoothing rod 237 to interface with the imaging electrode 16 the force is uniform across its length.

Within the cleaning portion of the imaging electrode tank is a cleaning brush 245 which is rotated in interfacing relation with the imaging electrode surface 244 of the imaging electrode 16. In place 'of the brush 245 another cleaning member such as disclosed in copending application Ser. No. 876,817, filed Nov. 12, 1969 now Pat. No. 3654,654 in the names of Christian D. Abreau, John S. Bernhard and Henry F. Chiavaroli and entitled Cleaning Apparatus could be substituted. The surface 244 is made of a material which prevents charge injection to sufficient particles to cause migration to the injecting electrode after they are struck with activatingradiation. The material can be baryta paper or Tedlar, a polyvinyl fluoride-or other suitable materials. It should have a resistivity of at least about 10 ohm-cm. In order to clean excess liquid and particles off the cleaning brush 245, two scraper blades 246 and 247 contact the cleaning brush 245. To remove all residual fluids andparticles from the surface 244 of the imaging roller 16, a squeegee 248 is mounted on a bracket 249. A stand pipe 250 is maintained within the cleaning section of the imaging electrode tank to remove excess liquids before they can spill over the tank splitting wall 222 and contaminate the applicator section of the system.

The remaining'section of the imaging electrode tank maintains motors and solenoids for operation of the various components during theimaging cycle.

The imaging electrode tank 26 is raised up from its neutral downward position by the cylinder 25 connected through a clevis mount to a crank arm 268 which is fixably attached to a shaft 269 maintaining eccentrics 270 thereon.

The imaging electrode tank 26 being moved by the operation of the cylinder 25 in cooperation with the eccentrics 270 is maintained for balance on a second eccentric fastened on a shaft 271 also located under the imaging electrode tank 26. When the cylinder 25 is operated it rotates the shaft 269 through the crank arm 268. Besides lifting the tank on the eccentrics 270, a chain 272 over a sprocket 273 mounted on the shaft 269 drives another sprocket 274 rotating the shaft 271 with eccentrics thereon. This double shaft-eccentric armanner similar to the functioning described with the brush 225 and the imaging electrode surface 244. A

tension spring 284 maintains the proper positioning of plicator roller 225 maintained thereon. Since both of the applicator rolls 225 and 226' are maintained in bearing contact with the support arms 228 and-229, 3 they are free to rotate independently of the positioning of the support 227. The motor 286 rotates the applicator roller 226 through a drive chain 287 and a sprocket 288 fixably mounted on a shaft extension of the shaft 231. The second applicator roller 225 is driven by a chain through sprockets 289 and 290. The applicator roller assembly is located within the tank 26 by locating plugs 291 and 292. The plugs are sealed by seals 293 and 294 to prevent leakage of suspension maintained within the lower portion of the imaging electrode tank 26.

The smoothing rod 237 interacts-with the surface 244 of the imaging electrode 16 by a solenoid SOL-B which through linkage 295 turns the crank arm 243 against a stop 296. A spring 297 anchored to an anchor pin 298 sets the spacing of the smoothing rod against the imaging electrode surface by holding the crank arm 243 against the stop 296. The smoothing rod 237 and the torque tube 240 which rotates it into position are metallic and electrically conductive. A bias clip 501 connects the torque tube to the shaft 216 of the imaging electrode 16 maintaining both and the smoothing rod at generally the same electrical potential.

The required electric potential is supplied through an electrical connector 503 and electrical contact brushes 504 which contact the shaft 216 of the imaging electrode. (The electrical source is not shown but should be sufficient to generate between roughly 300v. and 5000v. at the surface of the imaging electrode when it interfaces with the injecting electrode.) A bias clip 505 extends from the shaft 506 of the cleaning brush 245 to the shaft 216 of the imaging electrode giving it the same general potential as the imaging electrode.

The cleaning brush 245, unlike the suspension applicator apparatus around the imaging electrode 16 is I constantly contacting the surface 244 thereof. In a like manner so is the squeegee 248 held in the bracket 249.

The cleaning brush is rotated by means of a motor 507 which through a driving sprocket 508 rotates a chain 509 to drive the sprocket 510 on the shaft of the cleaning brush. Idlers 511 and 512 maintain the chain 509 on the sprockets as it moves along its path.

The imaging roller is driven by a single chain coming off the main drive system of the machine. The chain 530 drives a sprocket 531 on the imaging electrode such that the electrode moves in synchronous with the injecting electrode when there is contactbetween the two. 6

FIGS. 7 and 8 show an alternative apparatus to that of the previous figures. Here, the tank 540 has three operative sections: section 541 for applying ink; section 542 for cleaning the surface of the electrode 16 housed within the tank 540; and section 543 for wetting the electrode for a second imaging pass within the imaging cycle.

In the inking section of the tank 541 has a sump portion holding the imaging suspension 545 and having a drain 546 in the bottom thereof. A transport roll 547 is immersed in the sump portion of the tank section 541 to pick up imaging suspension as it rotates. In rotating interference with the transport roll 547 is an applicator roll 548 which is adapted to interface with the surface of the electrode 16 when the suspension application sectionof the apparatus is energized. Both rolls 547 and 548 are shafted for rotation in the same bracket 548 at a fixed interference witheach other so that the imaging suspension brought from the sump portion by the transport roll 547 is placed on and transported by The smoothing roller 550 although shown to be physically housed within the wetting section 543 of the tank 540 is functionally part of the suspension applica tor system within the tank section 541. This rod functions in the same manner as the smoothing rod 237 shown in FIG. 3. Although schematically represented as a roll 550 on a shaft 551 it is functionally and structurallyv the same as the smoothing rod 237 on a bracket 238 and a shaft 240 as shown in FIG. 3.

The cleanup section 542 of the tank 540 functions in a manner like the cleanup brush 245 section of the apparatus shown in FIG. 3. A cleaning brush 552 acquires cleaning materials 553 via an intermediate roll 554 joumaled for rotation to extend within the sump portion fillable with the cleaning material 553 and in an in FIG. 3. This prevents any materials accumulated on the electrode 16 from passing into the application or wetting tank sections.

The wetting section is used to supply carrier material to the electrode for a second pass of the injecting electrode during the imaging cycle. It has been found that this enhances the image formed on the injecting electrode for later transfer. The material used in the sump portion of the wetting section 543 is generally the same as the carrier material of the imaging suspension. Here an applicator roll 557 is positioned to dip into the sump portion holding the carrier material and to rotate with some liquid on it for interfacing with the electrode 16.

The electrode 16 then carries the liquid to the imaging zone between itself and the injecting electrode.

Each of the rollers shown with a sectioned shaft portion are driven by motors or other drive means not shown in these figures but similar to those of FIG. 5 driving comparable parts in FIG. 3. The wetting roller 557 would be driven in a manner similar to the cleanup roll 245 of FIG. 3. The wetting roll 557 is journaled in a bracket 558 which is mounted for rotation about a shaft 559 so.that the wetting roll 557 may be made to contact the electrode 16 as its function is desired.

The engagement of the various associated parts and apparatus with the electrode shown in FIG. 7 is accomplished by the use of the solenoids shown in FIG. 8. However, any suitable mechanism such as pneumatics, hydraulics, electrical or mechanical means may be used. The timing of the solenoids is related to the motion of the injectingelectrode and the necessities of the process in which the instant apparatus functions. The sequential actuation of the solenoids are accomplished by means well known in the art.

When the'suspension is to be applied to the imaging electrode 16 by the rotating applicator brush 548 within the inking section 541 of the tank 540, the solenoid SOL-D pulls linkage arms 560 and 561 in the direction indicated. This pushes the racket 549 upwards causing interference'between the applicator roll 548 and the surface of the blocking electrode 16. The crank arm 561 strikes the preset stop mechanism562 which determines the proper interference between the applicator roll 548 and the imaging electrode surface while a tension spring 563 maintains this position. The crank arm 651 attaches to a shaft 563 which pivots the ink applicator mechanism as shown in FIG. 7 for interference or removal from the surface of the imaging electrode 16. Theshaft 563 is positioned by locating plugs 564 in both ends of the tank 540.

The smoothing rod 550 interfaces with the imaging electrode 16 by action of the solenoid SOL-E through a linkage 565 which rotates the crank arm 566 against a set stop 567. This along with tension spring 568, positions the smoothing rod the proper distance from the I surface of the imaging electrode 16. The smoothing rod mechanism is the same as is shown in FIGS. 3, 5 and 6 and operates in a manner described in relation to those figures.

The solenoid SOL-F operates the linkage 569 to rotate a crank arm 570 against the stop 571 which in cooperation with a tension spring 572 rotates the shaft 559 for shuttling the bracket 558 and the wetting applicator roll 557 into and out of interface with the surface of the imaging electrode 16. As with the other em- The cycle operation with which this tank generally functions is such that on the first pass of the injecting electrode 1 through the imaging zone between it and the imaging electrode 16, the applicator roll 548 interacts with the imaging electrode 16. This supplies imaging suspension to the electrode 16. As the electrode passes by the smoothing rod 550, the imaging suspension is smoothed prior to entering the imaging zone. On the second pass of the injecting electrode through the imaging zone, the applicator roll 548 and the smoothing rod 550 have been disengaged by operation of the solenoids SOL-D and SOL-E respectively. The wetting roll 557 interfaces with thesurface of the imaging electrode 16 for the second pass of the injecting electrode 1 through the imaging zone. Therefore, the solenoid SOL-F is energized moving the wetting roller 557 to the surface of the imaging electrode 16. As the surface continues to rotate through the imaging zone it is cleaned by the continuous action of the cleaning brush 552.

The injecting electrode 1 continues to rotate through the transfer station where the image which has been twice through the imaging zone with the imaging electrode 16 is transferred to a sheet of support material. Then the injecting electrode is cleaned at the cleaning station A.

It is not necessary to move the tank 540 into and out of interference with the imaging zone although this may certainly be done. Nevertheless, this tank provides an imaging electrode capable of operating on a two or more cycle suspension application and background,

clean-up process without having to be moved relative to the interfacing position with the injecting electrode. Depending on the process steps desired, either the applicator or wetter functions can be energized in any order of time.

The systems of the apparatus described in the above figures operate on'the principal of a non-recirculating suspension application. That is to say, that any suspension not used for forming an image is removed from the system by action of the cleaning brush 245 and squeegee 248 in FIG. 3 or brush 552 and squeegee 556 in FIG. 7. The suspension and any other contaminants removed from the surface of the imaging electrode by the operation of the cleaning station is drained and circulated through a filter and then repumped into the cleaning station portion of the tank housing the various components surrounding the imaging electrode.

The materials supplied to the imaging electrode-surface could be solids as well as liquids and the matter removed from the surface could be both with or without contaminants gathered during imaging.

While this invention has been described with reference to the structures disclosed herein and while certain theories have been expressed to explain the experimentally obtainable results obtained, it is not confined to the details set forth; and this application is intended to cover such modifications or changes-as may come within the purposes of the improvements or the scope of the following claims.

What is claimed is:

1. Apparatus for imaging electrophore'tic particles suspensions including:

a first electrode adapted to support an image formed from the suspension;

at least another electrode with a surface capable of moving for contacting the suspension at a predetermined position between the electrodes;

means for applying an electric field across the suspension at the predetermined position;

means for exposing the suspension with activating electromagnetic radiation;

a tank adapted to support said another electrode for movement in the tank and having a plurality of sections around a position of the-surface of said another electrode including;

a first section having at least one applicator member adapted to contact the surface of said another electrode; g

a second section having cleaning means to remove matter from the surface of said another electrode, and

divider means to separate said first section from said second section in said tank.

2. The apparatus of claim 1 further including a squeegee adjustably positioned within the second section of said tank to contact the surface of said another electrode.

3. The apparatus of claim 1 wherein said tank has further associated therewith a means for moving said tank and said another electrode wherein said another electrode is moved into and out of the predetermined position.

4. The apparatus of claim 1' including a third section having wetting means to contact the another electrode surface and being capable of applying a liquid thereto.

5. The apparatus of claim 4 including second divider I means for separating said third section from said first and second sections.

6. The apparatus of claim 4 wherein said wetting means includes at least one roller positioned within said third section to contact the surface of the another electrode.

7. The apparatus of claim 4 including moving means operatively associated with said wetting means to move said wetting means into and out of contact with the surface of said another electrode. 

1. Apparatus for imaging electrophoretic particles suspensions including: a first electrode adapted to support an image formed from the suspension; at least another electrode with a surface capable of moving for contacting the suspension at a predetermined position between the electrodes; means for applying an electric field across the suspension at the predetermined position; means for exposing the suspension with activating electromagnetic radiation; a tank adapted to support said another electrode for movement in the tank and having a plurality of sections around a position of the surface of said another electrode including; a first section having at least one applicator member adapted to contact the surface of said another electrode; a second section having cleaning means to remove matter from the surface of said another electrode, and divider means to separate said first section from said second seCtion in said tank.
 2. The apparatus of claim 1 further including a squeegee adjustably positioned within the second section of said tank to contact the surface of said another electrode.
 3. The apparatus of claim 1 wherein said tank has further associated therewith a means for moving said tank and said another electrode wherein said another electrode is moved into and out of the predetermined position.
 4. The apparatus of claim 1 including a third section having wetting means to contact the another electrode surface and being capable of applying a liquid thereto.
 5. The apparatus of claim 4 including second divider means for separating said third section from said first and second sections.
 6. The apparatus of claim 4 wherein said wetting means includes at least one roller positioned within said third section to contact the surface of the another electrode.
 7. The apparatus of claim 4 including moving means operatively associated with said wetting means to move said wetting means into and out of contact with the surface of said another electrode. 